HeatmapRangeColorProvider Class
Paints heatmap cells according to value ranges.
Namespace: DevExpress.XtraCharts.Heatmap
Assembly: DevExpress.XtraCharts.v24.1.dll
NuGet Package: DevExpress.Charts
Declaration
[TypeConverter(typeof(LocalizableObjectTypeConverter))]
public class HeatmapRangeColorProvider :
HeatmapPaletteColorProviderRemarks
HeatmapRangeColorProvider paints heatmap cells based on value ranges to which cell values belong. Depending on the data adapter, the HeatmapRangeColorProvider uses HeatmapMatrixAdapter.Values or HeatmapDataSourceAdapter.ColorDataMember values to determine cell colors.
Use the HeatmapControl.ColorProvider property to assign a HeatmapRangeColorProvider object to the heatmap.
The RangeStops property allows you to specify color ranges. To do this, populate the RangeStops collection with HeatmapRangeStop objects. Specify the Value property for each range stop to define a color boundary. Set a range stop’s Type property to Percentage to define color ranges as percentages (in the [0..1] range). This can be helpful if the range of possible values is unknown.
If you want to have smooth transition between colors, enable the ApproximateColors property:
| ApproximateColors = true | ApproximateColors = false |
|---|---|
 |
 |
Use the color provider’s LegendItemPattern property to format legend items.
To define the color palette applied to cells, use the provider’s Palette or PaletteName property.
Example
This example shows how to use arrays of string and numeric values to create a heatmap:
Follow the steps below to create a heatmap:
- Add the HeatmapControl to the Form.
- Create a HeatmapMatrixAdapter object and assign it to the HeatmapControl.DataAdapter property.
- Use the adapter’s XArguments and YArguments properties to populate the heatmap with x- and y-arguments that are displayed along x- and y-axes.
- Assign a two-dimensional array of double values to the adapter’s Values property.
- Create a
HeatmapRangeColorProviderobject and assign it to the heatmap’s ColorProvider property. The HeatmapRangeColorProvider paints cells based on the value range to which the cell value belongs. - Add a HeatmapTitle to the heatmap’s Titles collection. Specify the title’s Text property.
- Use the heatmap’s Label property to configure cell label options. This example shows how to configure label text format.
using DevExpress.XtraCharts;
using DevExpress.XtraCharts.Heatmap;
using System.Drawing;
using System.Windows.Forms;
namespace HeatmapMatrixData {
public partial class Form1 : Form {
public Form1() {
InitializeComponent();
HeatmapMatrixAdapter dataAdapter = new HeatmapMatrixAdapter();
dataAdapter.XArguments = new string[] { "North", "South", "West", "East", "Central" };
dataAdapter.YArguments = new string[] { "Components", "Clothing", "Bikes", "Accessories" };
dataAdapter.Values = new double[,] {
{ 21.3, 50.1, 63.2, 64.4, 33.4 },
{ 32.3, 54.4, 81.3, 53.4, 54.9 },
{ 60.3, 49.1, 42.6, 48.4, 65.4 },
{ 45.3, 54.7, 70.3, 66.4, 56.6 }
};
heatmap.DataAdapter = dataAdapter;
Palette palette = new Palette("Custom") {
Color.White,
Color.SkyBlue,
Color.DarkBlue
};
HeatmapRangeColorProvider colorProvider = new HeatmapRangeColorProvider() {
Palette = palette,
ApproximateColors = true
};
colorProvider.RangeStops.Add(new HeatmapRangeStop(0, HeatmapRangeStopType.Percentage));
colorProvider.RangeStops.Add(new HeatmapRangeStop(20, HeatmapRangeStopType.Absolute));
colorProvider.RangeStops.Add(new HeatmapRangeStop(40, HeatmapRangeStopType.Absolute));
colorProvider.RangeStops.Add(new HeatmapRangeStop(60, HeatmapRangeStopType.Absolute));
colorProvider.RangeStops.Add(new HeatmapRangeStop(90, HeatmapRangeStopType.Absolute));
colorProvider.RangeStops.Add(new HeatmapRangeStop(1, HeatmapRangeStopType.Percentage));
heatmap.ColorProvider = colorProvider;
heatmap.Titles.Add(new HeatmapTitle { Text = "Sales by Categories" });
heatmap.Label.Visible = true;
heatmap.Label.Pattern = "{V}";
}
}
}